Session VIII - Polytrauma

Osseous Healing with Allograft and Demineralized Bone Matrix (DBM): The Adverse Effects of Smoking

Bruce H. Ziran, MD; Pooneh Hendi, MD; Kenneth Westerheide, MD; Wade R. Smith, MD; L. Caton, MD, University of Pittsburgh, Pittsburgh, PA

Introduction: The inhibitory effects of nicotine on bone metabolism, fracture healing, and fusion rates are known. Previous investigations at our institution showed a trend toward decreased healing rates with allograft + demineralized bone matrix (DBM) composites in smokers. We hypothesized that smoking may play a role in the poor performance of such non-autogenous composites in fracture reconstruction. We evaluated the effects of smoking on bone grafts composed of cancellous allograft and Grafton (DBM) (Osteotech).

Methods: A prospective protocol was established for all bone-grafting procedures. The composite graft was composed of cancellous allograft chips and Grafton in a 4:1 ratio by volume. Patients included in the study had atrophic nonunions or fractures with a segmental defect or severe comminution that required bone grafting. Patients were excluded if they received iliac crest bone graft, a bone stimulator, or had a closed head injury. Patients were followed at routine intervals with a minimum follow-up of 18 months. Healing was clinically and radiographically determined.

Results: The average follow-up time was 36 weeks for the 107 patients (60 men and 47 women, with a mean age of 42 years). Fifty-three patients were in the nonunion group and 54 in the fracture group. Overall, 87 (78%) of the 112 bone-graft sites were considered healed. Of the 25 (22%) failed cases, there were 8 (7%) sites that successfully achieved union on second bone grafting, providing a cumulative success rate of 85% (95 of the 112 sites). There were no differences in the number of co-morbidities between the 52 smokers and the 55 nonsmokers. A substantial smoking history was present in 18 of the 25 failed cases (72%). Of the 55 nonsmokers, 48 healed uneventfully (87%), whereas only 34 (65%) of the 52 smokers had an uncomplicated healing course. Eleven of the 16 (70%) fractures that failed to heal were in patients who were smokers; 23 of 28 (83%) sites in nonsmokers healed, whereas only 20 of 31 (66%) fracture sites in smokers healed. Although the odds ratio was 2.5, these differences were not significant (P = 0.2). Forty-four of the 53 (83%) patients with nonunions healed; 7 of the 9 (77%) failures were in smokers. In this group, the odds ratio was 5.0, but these differences were not significant (P = 0.1).

Discussion: We found that allograft and Grafton DBM (Osteotech) may not perform well as a treatment for fractures and nonunions in patients who smoke. Although nonsmokers had satisfactory outcomes, we noted a clear decrement in the performance rate (66% in the fracture group and 72% in the nonunion group) of allograft/Grafton (Osteotech) among smokers. We have since discontinued the use of allograft/Grafton (Osteotech) in this patient population and are investigating other alternatives.

Conclusion: The composite graft of allograft and DBM should be used with caution in smokers.